[computer-go] Experiments with UCT

[steve uurtamo]

> One issue that springs to mind is ko: sente moves
> are also ko threats,
> so shouldn't always all be played before playing a
> gote move.

well, the presumption is that L&D problems are
done with, so ko should only be worth 1/2 point
or so, right?  in which case, you could use
zero-point sente moves first (threatening to break
a bamboo joint, for instance).

thinking more generally about ko threats earlier
in the game, why not store a ko-value for each move?
the ko value for any single move could simply be
the sum of the move value and the result of being
allowed to play its best followup move immediately
afterward.

the idea would be to then search and play moves
sorted by ko-value during a ko fight, excluding
any moves from the list that would require the
threat or its followup to take place inside the
ko itself.

> I personally think this is too hard to do
> accurately. Better to just try
> all combinations of reasonable moves. (Or when "all"
> takes too long,
> then a reasonable sample, as in monte-carlo go.)

hm.  the thing is, this might be a way to prune
the list of things to search in advance, which
should allow for more accurate endgames.  i
think that past a certain point in the game,
there's an unambiguous way to play in order to
maximize your score.

i don't know what that way is, of course, which
is why i'm hoping to get some public opinion on
it, but very good players seem to have unambiguous
and congruent opinions about the correct order of
the last 10-15 moves or so.  which can amount to
a swing of 5+ points over a sloppier move
ordering.

i.e. this is the difference between when you can
search out the entire rest of the likely move tree
and the move or two before when you can't, but
where the sequences of endgame moves are so few
that it becomes an ordering problem instead of
a searching problem.

s.

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